Benchmark Results: Random Read/Write

The following results are highly relevant for booting an operating system like Windows. The real-world differences between a hard drive and SSD probably won't be as pronounced as these more synthetic results, but they're still very noticeable.

According to CrystalDiskMark, the hard disk deals with 4 KB random blocks at a mere 1.6 MB/s, while the SSD writes at 19.7 MB/s and reads at 70.6 MB/s.

Performance improves with a deeper command queue, which more completely saturates the SSD's multi-channel architecture. The hard drive also demonstrates a performance gain thanks to re-ordering of operations through NCQ, but the boost is much smaller.

For large block sizes (512 KB in this benchmark), the hard disk is able to achieve much better performance than we've seen. But the SSD is operating close to its performance limit; a faster drive based on 6 Gb/s-capable hardware would put more distance on the Seagate disk.

At a queue depth of 64 (that is, with 64 commands pending), the SSD is 40 to 50 times faster than the hard disk.

Iometer shows that the 128 GB Samsung 470 can handle 28 000 I/O operations per second. The hard disk’s value of 102 operations per second seems incredibly slow in comparison.

Repeating the same random test for write operations illustrates the drawback of SSDs, which have to read, erase, and rewrite blocks in order to write data to flash memory. Be that as it may, the SSD is still ten times faster than the hard disk.